Orchard heater



E. R. YUNDT ORCHARD HEATER July 9, 1940.

Filed Dec. 14, 1957 Patented July 9, 1940 UNITED 1 starts mum orrics This invention relates to and has for a primary object ,the provision of an improved orchard heater of simple design and economical in manufacturing cost, embodying certain novel features 5 of construction whereby the heat generated will be directed outwardly by radiation from the heater instead of upwardly through the staokand so arranged to minimize, if not to quite completely eliminate, the smudge, soot or smoke which usually emanates from an orchard heater.

More detailed objects are as follows:

First: To introduce air from the atmosphere into the mixing chamber at points intermediate the two combustion chambers for mixture with the gas generated in the primary combustion chamber while said gases are not in a process of combustion.

Second: To deliver the aforesaid mixture of air and gas into the secondary combustion chamber through a relatively shallow peripheral'passage, usually of annular form, for the purpose ofobtaining a maximum mixture of the gas'with. air admitted in gradually decreasing volume from the atmosphere at successive points upwardly in the secondary combustion chamber, as it may be required for complete combustion.

Third: To vary the area of the secondary combustion chamber from the bottom thereof .upwardly in the direction of the stack so thatthe open area of the secondary combustion chamber, at its top, will be substantially less thanthe area of the same at its bottom, thereby tending to retard the upward flow of gas and toinsure perfect combustion before the products of combustion leave the secondary combustion chamber and pass out through the stack.

Fourth: To provide at the bottom of the inner drum a bafiie against which the flames and the hot gases generated in the primary combustion chamber will be directed and diverted outwardly toward the periphery of the outer drum, between the wall of which and said baffle a restrictedpassage for the unconsumed gas is provided, saidrestricted passage being of substantially less area than the portion of the secondary combustion chamber adjacent thereto.- 1

Another object is to provide a; readily collapsible device embodying separableunitswhich may be quicldy assembled and disassembled and compactly nested for the purpose of packing and shipping.

Other objects may appear as the desc'ption progresses. v

I have shown in the accompanying drawing-a preferred form of my invention, subject to modi- .the'-'wall of the outer drum, as shown in Fig. 1,

. fication/within the scope of the appended claims,

without departing from the spiritof my invention. 1 V

- Referring to the drawing;

Fig. {1 is a vertical section partly in elevation, 5

1 Fig. 2 is a section of the same on line 2-2v of Fig. 1,.

. Fig.3 is a fragmentary plan as viewed on line 3- 3 of Fig. 1, and

4 is a perspective view of a bafile which is .10

removaloly mounted near the bottom of the outer drum and forms a support for the inner drum.

Briefly described, my invention includes a base A forming a fuel container and a primary combustion chamber, a secondaryunitembodying an 1 6 outer drum Band an inner drum C concentrically supported onthe base A, abaffle plate D forming a bottom and a support for the inner drum C, and a stack E which is mounted upon the outer dru B. Base A is provided with a tubular mem- :20 her i-projecting upwardly at an angle from the .top 2, and provided with a suitable damper 3, and a cap 3a, which latter is removable from the :tubular member I for the purpose of inserting a torch or taper in order to fire the fuel held with- 25 in the base A. The damper 3 is arranged to regu ,late the opening and closing of one or more oriifices 4 forvthe purpose of providing a draft. Base "A also has an upwardly extending neck" 5 which lis-adapted to telescopically receive a neck 6 eX- 30 ,tendingfroma member l whichis adapted-to reof the inner drum and the top l2'of the outer 50 It will be noted that the bafile D has a web l3 which extends outwardly beyond an annular flangev it thereon in the direction of, but not quite in contactwith, the wall of the outer drum 55 B so as to provide a restricted passage between the periphery of the bafile D and the wall 9 of the outer drum. The area of said passage is substantially less than the area of the secondary combustion chamber at points adjacent thereto. The baflie D and the inner drum C are supported as by means of a pair or more of rods l5, I5 which extend through apertures l6, l6, etc., of the outer drum B, and through apertures l8, l8, etc., in lugs I9, l9, etc., of the baffle D. Said baffl'e and said inner drum are centered with respect to the outer drum by means of washers 20, 20, etc., which fit between the drum B and lugs l 9 of baffie D. The rods l5 extend below the web l3 of baffle D and serve to support the baffle and the inner drum C concentrically in the heater. The annular flange M is telescoped by the wall 2| of inner drum C. The drum B has an upwardly extending neck or collar 22 which is telescoped by the stack E and removably receives said stack.

It will be noted, by reference to Fig. 1, that that portion within the outer drum and below bafile D constitutes a mixing chamber 22 wherein generated gas arising from the primary combustion chamber a in the uppermost portion of base A, after passing through the neck 5, is mixed with air from the atmosphere, as by means of a series of perforations 23, 23, etc., while the secondary combustion chamber I8 is also in communication with the atmosphere at a plurality of points between its bottom and its top, as by means of groups of vertically spaced perforations 24, 25 and 26. The size, number and spacing, both laterally and vertically, of said last mentioned perforations depend upon the requirements of use, that is to say, the relative volumes of air necessary to introduce into the secondary combustion chamber Iii at different elevations for the purpose of obtaining perfect combustion. For instance, the lowermost series of perforations 24 are necessarily greater in number and have a greater total area than the second set of perforations 25, and the number,'size and spacing of the uppermost set of perforations should be substantially less than the group of perforations 25.

The aforesaid conditions arise from the fact that only the generated combustible gases in the primary combustion chamber a will pass upwardly into the secondary combustion chamber l0 around the periphery of the bafiie D, and a maximum amount of air is necessary at the bottom of chamber D in order to effect initial combustion of the gases, chamber D being gradually decreased in area as combustion progresses, and as the gases rise therein the amount of air necessary to continue perfect combustion is necessarily gradually decreased until finally when the gases rise to the level of the top H of the inner drum C, there will be little, if any, unconsumed gas emitted through and from the stack E. Thus, soot and smoke will be almost, if not quite, completely eliminated from the operation of a heater such as disclosed herein.

It will be readily understood that in the operation of orchard heaters, it is highly desirable that a maximum dissipation of the heat from a heater should be obtained in order to prevent frosts and consequent damage to fruit. Smudge, which is, in effect, unconsumed carbonaceous products of combustion, is highly undesirable. In other types of heaters, a substantial amount of the generated heat is emanated through the stack and, of course, rises directly upwardly from the stack, whereas in a heater embodying my improvements, the

walls of the drums B and C form extensive radiating surfaces which tend to direct the heat outwardly in substantially horizontal planes for a distance from the heater, by reason, primarily, or largely at least, of the fact that the secondary combustion chamber H] is of variable area from the bottom to top, with a minimum area at the top, thereby tending to retard the upward movement of the gases in process of combustion, and

1 said drums will be thereby heated to a higher temperature than would be otherwise possible. The effective area, therefore, of an orchard heated by a single unit would be substantially increased over other methods and devices which tend to direct the heat upwardly, either directly or indirectly from the fuel container A.

It will be quite apparent that the arrangement shown and described is only illustrative of the improved features of my invention, and that the relationship between the several units of my heater may be modified to meet varying conditions of use and for increasing its efliciency within the scope of the claims hereto appended, without departing from the spirit of my invention.

I claim:

1. An orchard heater comprising: a fuel receptacle open to the atmosphere and providing a primary combustion chamber, a radiating unit superposed thereon and including an inner drum and an outer drum peripherally spaced apart so as to provide between them a secondary combustion chamber open to the atmosphere and of greater area at its bottom than at its top, an imperforate baflie plate at the bottom of said inner drum and spaced from the bottom of said 1 outer drum for providing a mixing chamber open to the atmosphere and intermediate said primary combustion chamber and said secondary combustion chamber, said bafiie being extended laterally outwardly from said inner drum and peripherally spaced from said outer drum so as to provide a restricted passage for gas generated in said primary combustion chamber of substantially less area than said secondary combustion chamber, and a stack superposed on said outer drum and in communication with said secondary combustion chamber.

2. An orchard heater comprising: a fuel receptacle open to the atmosphere and providing a primary combustion chamber, a radiating unit superposed thereon and including an inner drum and an outer drum peripherally spaced apart so as to provide therebetween a secondary combustion chamber open to the atmosphere and of greater area at its bottom than at its top, an imperforate baffle closing the bottom of said inner drum and spaced from the bottom of said outer drum for providing a mixing chamber open to the atmosphere and intermediate said primary combustion chamber and said secondary combustion chamber, said baffle being extended laterally from said inner drum and peripherally spaced from said outer drum so as to provide a passage for gas generated in said primary combustion chamber of substantially less area than said secondary combustion chamber, a stack superposed on said outer drum and in communication with said secondary combustion chamber, and means for supporting said bafiie on said outer drum.

3. An orchard heater comprising: a fuel receptacle having a primary combustion chamber open to the atmosphere, a unit superposed thereon including an outer drum in the form of a truncated cone, 2, baffle supported on said outer drum at a point spaced upwardly from the hottom of said outer drum and providing a mixing chamber open to the atmosphere above and in communication with said primary combustion chamber, an inner drum supported on said outer drum and closed at its lower end by said baflle and having its wall spaced from the wall of said outer drum to a substantially greater degree at the bottom of said inner drum than at the top thereof, thereby providing a secondary combustion chamber between the walls of said drums which gradually decreases in area upwardly. a stack in communication with the upper extremity of said secondary combustion chamber, and means for introducing air to said secondary combustion chamber at points above said bafile, said bafile extending laterally between said drums and having its outer edge spaced from the wall of the outer drum to define a restricted passage between the mixing and secondary combustion chambers.

4. An orchard heater comprising: a fuel receptacle, means associated therewith for supporting in and confining to said receptacle a primary combustion of fuel therein for generating gases,

means defining a mixing chamber having atmos-- pheric air intaking means and arranged to receive gases from said receptacle without effecting combustion of the gases therein, means defining above said chamber an upright combustion chamber having a surrounding heat radiating wall exposed to the atmosphere and provided with atmospheric air intaking means, means for defining between said chambers a restricted communicating passage disposed to discharge gases upwardly along the inner side of said surrounding wall, and a stack communicating with the upper end of said combustion chamber, said combustion chamber gradually decreasing in area toward its upper end.

EMERY R. YUNDT. 

